The Effect of Methylphenidate and Clonidine on Response Inhibition and State Regulation in Children with ADHD

Abstract

The goal of this study was to evaluate the effect of methylphenidate (MPH) and clonidine in comparison with placebo on response inhibition and state regulation in children with Attention Deficit Hyperactivity Disorder (ADHD). The study utilised a double-blind crossover design in which children were randomly assigned without replacement to placebo, MPH, and clonidine following baseline assessment. The primary dependent measures were derived from children's performance (reaction time and errors) on a GO-NO GO task under three conditions that altered the inter-stimulus interval (ISI) for presented GO-NO GO stimuli : ISI of 1 sec (fast condition), 4 sec (medium condition), and 8 sec (slow condition). Findings indicated no difference in task performance between groups treated for 7 weeks with placebo, MPH, and clonidine. We concluded that the state regulation problem in ADHD is resistant to MPH and clonidine.

Acute neuropsychological effects of methylphenidate in stimulant drug‐naïve boys with ADHD II – broader executive and non‐executive domains

“…Further, the present study fails to support the findings of two earlier studies which utilised the Go/NoGo task and demonstrated an enhancement of inhibitory processes with acute MPH (Trommer et al, 1991; Broyd et al, 2005). However, Van der Meere and colleagues also conducted a double‐blind, placebo‐controlled study of strictly defined drug‐naïve children with ADHD (Van der Meere et al, 1999) and found that stimulant medication (chronically administered) failed to enhance performance on a Go/NoGo task. It is also possible that the differences between these studies could be a consequence of the Go/NoGo tasks used.…”

“…Berman, Douglas, & Barr, 1999; Shue & Douglas, 1992; Trommer, Hoeppner, & Zecker, 1991; Scheres et al, 2003). However, other studies have failed to demonstrate enhanced inhibitory performance in medicated children with ADHD (Ross, Hommer, Breiger, Varley, & Radant, 1994; Van der Meere, Gunning, & Stemerdink, 1999).…”

The effect of methylphenidate on sustained attention among adolescents with attention-deficit hyperactivity disorder

“…Recent studies have shown the positive effects of MPH in improving speed and variability in responding to a stimulus (Spencer et al, 2009); postural stability when an additional task is performed (Jacobi-Polishook, Shorer, & Melzer, 2009); producing reinforcing effects (Kollins, English, Robinson, Hallyburton, & Chrisman, 2009); and enhancing their social behavior (Jahromi et al, 2009). In exploring the aspects of attention, it was found that MPH improved performance in divided attention (Keith & Engineer, 1991); selective attention (Van Der Meere, Gunning, & Stemerdink, 1999); focused attention (Musten, Firestone, Pisterman, Bennett, & Mercer, 1997); and measures of memory or executive functioning (Kempton et al, 1999;Zeiner, Bryhn, Bjercke, Truyen, & Strand, 1999). Specifically, in sustained attention, it was found that MPH improved the performance of sustained attention/vigilance as compared to no treatment (Riccio, Reynolds, & Lowe, 2001;Tillery, Katz, & Keller, 2000;Tucha et al, 2006).…”

Cognitive effects of immediate-release methylphenidate in children with attention-deficit/hyperactivity disorder

“…Lengthy test administration time, such as that which is often observed with vigilance tasks, may also inflate performance variability by increasing fatigue and/or decreasing participant compliance (e.g., task duration greater than 20 min, van der Meere et al, 1999). This issue is pertinent to the study of ADHD, as researchers may deliberately employ tasks with a long duration in an effort to magnify deficits in sustained attention.…”